South entrance channel dredging to start soon, continue into February

In an effort to improve navigation through Marina del Rey and clear away accumulated material, construction crews plan to begin dredging the south entrance channel of the Marina later this month.

The U.S. Army Corps of Engineers Los Angeles District has awarded a $1.8 million contract to CJW Construction of Santa Ana to dredge sand material from the south entrance channel. The project, which is slated to start late this month, is expected to cost approximately $3 million.

The maintenance dredging project will involve removing approximately 50,000 cubic meters of material near the south entrance channel, said Jim Fields, Army Corps of Engineers project manager. Construction crews are working to clear out “unsuited material” and help improve access through the south entrance channel, whose depth is currently about one-third to one-quarter reduced by material, Fields said.

Sgt. Mike Carilles of the Los Angeles County Sheriff’s Department Marina del Rey Station noted that the south entrance is currently at 25 to 30 percent of its design depth, but that the situation does not present a hazard to boaters.

“It’s to make sure the south entrance is clear and it’s something that’s routinely done,” said Sheriff’s Lt. Reggie Gautt, the Marina harbormaster. “[The Marina] is a man-made harbor and unfortunately you get a lot that’s deposited there.”

The south entrance channel dredging comes after the north entrance channel was dredged last year. The south channel was last dredged in 2000.

Material from the south entrance will be hydraulically pumped to Parking Lot 3 at Dockweiler State Beach in Playa del Rey, where the contractor will separate the clean sand from the chemically-challenged fine-grained material, Fields said.

While sand material from the north entrance usually comes from the beach and is cleaner, south channel material mostly comes from Ballona Creek and is typically unsuitable for open water placement, requiring a treatment process, he said.

The contractor plans to use a special technique incorporating “hydrocyclone technology” to produce high quality beach sand that is used to nourish beaches to the south. The technology was produced over several years by a team of state, federal and local agencies, including Santa Monica-based Heal the Bay. The team was led by the Army Engineers and the engineering firm Anchor Environmental of Seattle.

“The application of this technology could change the dredging industry throughout the world, so we’ll be monitoring this project closely,” Fields said.

Army Corps officials note that the Marina del Rey harbor, which is home to about 5,000 boaters, is considered vital to the safety and security of Los Angeles International Airport and the region.

“The County of Los Angeles is excited about the opportunities this project offers in finding a long-term solution for removing contaminated sediments in the Marina del Rey harbor south entrance, as well as in converting much of that material into clean sand that can be placed on our beaches,” County Supervisor Don Knabe said.

Gautt said the dredging project will “definitely keep our waterways clean and clear, which will not only benefit boaters but others, such as recreational swimmers.”

Officials said they do not plan to close the south entrance during the project, which is expected to be completed in February.